Hello!
I've seen this bug, but never had it happen to me personally. However, I did have the problem where ALT+TAB wouldn't work at all. Any how, have you tried these steps:
-Opening a app in the background to see if it won't freeze
-Uninstalling your game
-Removing all mods, and save edits
If non of these recommendations have worked, or are working. Read through this SCS-Blog to see if their fixes/problems correlate to the issues you're having.
-https://forum.scssoft.com/viewtopic.php?t=290727
If your problems/issues have been resolved or fixed please do drop a check mark
Have a good day